Bindings for fan connected to GPIO lines Required properties: - compatible : "gpio-fan" Optional properties: - gpios: Specifies the pins that map to bits in the control value, ordered MSB-->LSB. - gpio-fan,speed-map: A mapping of possible fan RPM speeds and the control value that should be set to achieve them. This array must have the RPM values in ascending order. - alarm-gpios: This pin going active indicates something is wrong with the fan, and a udev event will be fired. - #cooling-cells: If used as a cooling device, must be <2> Also see: Documentation/devicetree/bindings/thermal/thermal.txt min and max states are derived from the speed-map of the fan. Note: At least one the "gpios" or "alarm-gpios" properties must be set. Examples: gpio_fan { compatible = "gpio-fan"; gpios = <&gpio1 14 1 &gpio1 13 1>; gpio-fan,speed-map = <0 0 3000 1 6000 2>; alarm-gpios = <&gpio1 15 1>; }; gpio_fan_cool: gpio_fan { compatible = "gpio-fan"; gpios = <&gpio2 14 1 &gpio2 13 1>; gpio-fan,speed-map = <0 0>, <3000 1>, <6000 2>; alarm-gpios = <&gpio2 15 1>; #cooling-cells = <2>; /* min followed by max */ };